1. Field of the Invention
The present invention relates to an ink jet imaging apparatus that prints using at least one ink jetting printhead, and, more particularly, to a method for use in achieving velocity optimization for the printhead.
2. Description of the Related Art
An ink jet imaging apparatus, such as an ink jet printer, forms an image on a print medium, such as paper, by ejecting ink onto the print medium. Such an ink jet printer may include a reciprocating printhead carrier that transports one or more printheads across the print medium along a bi-directional scanning path defining a print zone of the printer. The printhead is in fluid communication with an ink supply.
Such a printhead includes a plurality of nozzles having corresponding ink ejection actuators, such as resistive heater elements. The manufacture of printheads involves certain manufacturing tolerances resulting in manufacturing variations, which in turn result in printheads that require various amounts of energy to attain appropriate drop velocities for the ink. Thus, typically, from printhead to printhead, the amount of energy required to obtain a sufficiently high drop velocity varies. Because of these manufacturing variations, an energy level for driving such printheads typically will be selected so that most printheads will attain a certain minimum drop velocity, without any attempt at velocity optimization.
One prior method for performing velocity optimization for a printhead involves the printing of line patterns at various fire pulse energy levels. The line patterns are then scanned, e.g., by as scanner or optical sensor, and the scanned data is processed through special algorithms to select a desired energy level. Such a method, however, necessitates that the imaging apparatus have some sort of scanning device in order to perform the velocity optimization, requires the use of ink for generating the line patterns, and requires user interaction at least to the extent of feeding the page having the line pattern back through the imaging apparatus for scanning.
What is needed in the art is a method for performing velocity optimization that does not require, for example, the generation or scanning of a line pattern.